Titanium oxide having a monoclinic β-type structure (hereinafter referred to as TiO2 (B)) has recently been noted as an active material for a non-aqueous electrolyte battery (see JP-A 2008-34368 (KOKAI), JP-A 2008-117625 (KOKAI) and WO 2009/028553 A1). The number of lithium ions which can be inserted and released per unit chemical formula of spinel type lithium titanate (Li4Ti5O12) which has heretofore been put into practical use is three. Therefore, the number of lithium ions which can be inserted/released per titanium ion is 3/5, i.e., the theoretical maximum number is 0.6. In contrast, in TiO2(B), the maximum number of lithium ions which can be inserted/released per titanium ion is 1.0. Therefore, TiO2(B) has a theoretical capacity of about 335 mAh/g which is an excellent property.